The flowering season for many rhododendrons and
azaleas is completed by June, but there are other varieties available to extend
the blooming period even into September. Many of these late bloomers are
derived from the plumleaf azalea, Rhododendron prunifolium.

Rhododendron prunifolium, a native
deciduous plant of Georgia and Alabama, grows into a large shrub, often
attaining a height of 15 feet in the wild. The orange to orange-red or
even red flowers, appearing in July and August, have a tubular shape with
graceful long stamens. They stand out in bright profusion against the dark
green foliage. The flower buds are usually striped in appearance.
Even with its southern heritage, R. prunifolium has proven to be
completely hardy and a "good doer" on Long Island, and certain clones have
demonstrated hardiness to -20°F. A semi-shady planting site is recommended
to preserve the flowers, especially during the heat of summer.

There are several selections of the species which
include the following: "Summer Sunset" selected by the Crown Estate
Commissioners, Windsor, with vivid red flowers; 'Hohman' chosen by Hohman for
its deep reddish-orange flowers; and 'S. D. Coleman' selected by David Leach and
enhanced by vibrant reddish-orange flowers.

Several hybridizers have tried to lengthen and
extend the flowering time by using R. prunifolium as a parent. It
has proven to be surprisingly hardy as well as a good parent. David Leach,
while at North Madison, Ohio, made several crosses utilizing the 'S. D. Coleman'
form of R. prunifolium to extend the blooming season. Among his
July Series are 'July Jester' (R. prunifolium 'S. D. Coleman' x R.
bakeri 'Scarlet Salute') with vivid reddish-orange flowers and a medium
height; 'July Jewel' (R. prunifolium 'S. D. Coleman' x R. bakeri
'Scarlet Salute') showing a deep reddish-orange color and semi-dwarf habit, and
'July Jubilation' (R. prunifolium 'S. D. Coleman' x 'Cream Puff') another
semi-dwarf with strong reddish-orange flowers.

Weston Nurseries of Massachusetts had an
ambitious hybridizing program for summer blooming azaleas. It was begun in
the 1930s by Edmund Mezitt and is carried on today by his son Wayne. Among
their R. prunifolium hybrids are: 'Cherry Bomb', a July bloomer with
large cherry red flowers; 'Tangerine Glow' bringing a show of dark orange
flowers from July into August; 'Everglow' with dark orange-red flowers from July
into August; and 'Pennsylvania' blooming in July with light pink flowers.

Jim Cross of Environmentals on Long Island has
just recently introduced a wonderful new hybrid called 'Sweet September'.
The plant blooms reliably in mid-September with clear pink flowers and red
stamens. It has an upright habit.

Roslyn Nursery of Dix Hills plans to release in
1995 a new September blooming form of R. prunifolium with large
orange-red flowers. The plant has bloomed profusely on Long Island for the
past six years, and it is an attractive shrub year round.

These plants will become more popular in the
future as the public realizes their exciting possibilities. The late
bloomers offer bright colors when many people are spending more time in the
outdoors. These azaleas are easy to grow, reliably hardy, shade tolerant,
and have attractive foliage. They should have a place in every garden,
especially those of ARS members